I. Field of the Invention
The present invention relates to a catheter having a flexible proximal portion and a rigid distal portion whose end has a beveled needle tip for direct insertion through a barrier without requiring an introducer tool to puncture a site of placement. The present invention includes a catheter assembly incorporating the catheter along with a hand-operable implantation grip, as well as methodology for introducing the catheter into a percutaneous drug delivery port implanted in a person.
II. Description of the Prior Art
Employment of a catheter for delivering a fluid medication to a patient is well known. Such a known catheter typically is a flexible tube whose distal end resides within the patient and whose proximal end has a hub fitting such as Luer-type fitting for connection to a reservoir from which medication is dispensed for travel through the catheter and into the patient. The distal end of the catheter may feed, for example, directly into a vein of the patient, or it may feed into a drug-delivery port implanted percutaneously within the patient. Such a port usually comprises a reservoir having a resilient septum disposed nearest the skin and through which the distal end of the catheter must pass to thereby deliver medication into the reservoir for subsequent outward flow to a medication site.
Because the entire prior-art catheter is constructed of a flexible material, the distal end thereof cannot be introduced into the patient without first employing another device to puncture the site of entry and provide an opening through which the distal end can pass. One approach for introducing the catheter is to use a hollow-needle syringe disposed within the catheter such that the needle produces an opening and simultaneously carries the surrounding catheter portion through the opening to the desired destination site. Thereafter, the syringe is withdrawn and the catheter remains. When this approach is used in entering a percutaneous drug delivery port, however, the syringe needle causes coring of the septum which, in turn, can cause the port to leak fluid through the produced hole. When this occurs, leaked medication originally intended to be delivered from the port to a specified body site is not available.
One approach for solving the coring problem when introducing a catheter into a percutaneous port has been employment of a solid stylet disposed within the catheter during catheter introduction and projecting from the distal end thereof such that the stylet punctures the septum and simultaneously carries the surrounding catheter portion through the puncture and into the reservoir of the port. The stylet, which is subsequently withdrawn, does not produce coring because it is of solid construction. Both U.S. Pat. Nos. 5,135,502 and 5,403,283 teach solid stylets, with the latter patent additionally teaching an insertion tool whose construction can include stylet isolation means activated after catheter insertion to thereby guard against an inadvertent needle stick to a health care provider.
While using a solid stylet as described above alleviates the coring problem while entering a percutaneous port, for example, the catheter still can be introduced only by using a separate piercing tool. This necessity requires the use of, as well as the disposal of, the stylet piercing tool which, because it has entered a patient site, can be a health hazard after withdrawal from the patient and prior to final disposal.
It is therefore apparent that a need is present for a catheter whose construction permits ready introduction within a patient site. Accordingly, a primary object of the present invention is to provide a catheter comprising a flexible proximal portion and a rigid distal portion, with the distal portion having a needle tip for directly piercing a barrier and entering a site for medication delivery.
Another object of the present invention is to provide a catheter wherein the needle tip of the distal portion is beveled to thereby eliminate coring by the needle tip.
Yet another object of the present invention is to provide a catheter assembly incorporating a catheter having a beveled needle tip and a hand-operable implantation grip whereby catheter placement and insertion is aided.
Still another object of the present invention is to provide a method of catheterizing an implanted percutaneous drug delivery port through the utilization of a catheter assembly to achieve implantation of a catheter having a needle tip beveled to thereby enter a septum of the port without coring the septum during entry.
These and other objects of the present invention will become apparent throughout the description of the invention which now follows.